Switching power converters convert an input voltage to an output voltage. In some cases, the output voltage is selectable based on the type and capabilities of the device coupled to the power converter (e.g., systems that implement Universal Serial Bus (USB) 3.0). When switching power converters implement a synchronous rectifier in the form of a field effect transistor (FET), low output voltage may make it difficult for the secondary-side controller to make the FET fully conductive.